Carriage-connecting device in a serial printer

Abstract

A serial printer is disclosed in which a serial printer body is connected to a carriage via a cable. The carriage is driven by electric power supplied through the cable, and signals are also transmitted between the serial printer body and the carriage through the cable. The cable comprises a sheet-like substrate and a plurality of conductive strips which are formed on the sheet-like substrate and which extend in a longitudinal direction of the sheet-like substrate. The plurality of conductive strips includes at least one wide conductive strip for supplying the electric power and at least one narrow conductive strip for transmitting the signals. The wide and narrow conductive strips are arranged such that noise created by the electric power supplied by the wide conductive strip does not interfere with the signals transmitted in the narrow conductive strip.

What is claimed is: 
     
       1. A carriage-connecting device in a serial printer, comprising: a serial printer body;   a cable;   a carriage, which has a printing head and a sensor, connected to said serial printer body via said cable,   said printing head is driven by electric power supplied to said printing head through said cable,   signals, which are generated by said sensor, are transmitted between said serial printer body and said carriage through said cable,   said cable comprises a sheet-like substrate and a plurality of conductive strips which are formed on said substrate and said conductive strips extend in a longitudinal direction of said sheet-like substrate,   said plurality of conductive strips comprise at least one wide conductive strip supplying said electric power and at least one narrow conductive strip for transmitting said signals,   said at least one wide conductive strip and said at least one narrow conductive strip are spaced on said sheet-like substrate in such a manner as to reduce the amount of noise caused by said electric power in said signals transmitted in said at least one narrow conductive strip.   
     
     
       2. A carriage-connecting device as claimed in claim 1, wherein said sheet-like substrate comprises a first layer which includes a first substrate and at least one of said plurality of conductive strips and comprises a second layer which includes a second substrate and at least one other of said plurality of conductive strips. 
     
     
       3. A carriage-connecting device as claimed in claim 1, wherein said at least one narrow conductive strip is located at one side of said sheet-like substrate and said at least one wide conductive strip is located at another side of said sheet-like substrate wherein said another side of said sheet-like substrate is opposite to said one side of said sheet-like substrate. 
     
     
       4. A carriage-connecting device as claimed in claim 2, wherein: said at least one narrow conductive strip is located at one side of one of said first substrate and said second substrate; and   said at least one wide conductive strip is located at another side of one of said first substrate and said second substrate,   wherein said another side is opposite to said one side.   
     
     
       5. A carriage-connecting device as claimed in claim 4, wherein said at least one narrow conductive strip is located on said first substrate and said at least one wide conductive strip is located on said second substrate in such an manner that said at least one narrow conductive strip is not disposed directly above or below said at least one wide conductive strip. 
     
     
       6. A carriage-connecting device as claimed in claim 3, wherein said at least one narrow conductive strip is no wider that 0.4 mm. 
     
     
       7. A carriage-connecting device as claimed in claim 5, wherein said at least one narrow conductive strip is no wider that 0.4 mm. 
     
     
       8. A carriage-connecting device as claimed in claim 4, wherein said first substrate and said second substrate are separated by a distance of at least 1 mm. 
     
     
       9. A carriage-connecting device as claimed in claim 7, wherein said first substrate and said second substrate at separated by a distance of at least 1 mm. 
     
     
       10. A carriage-connecting device as claimed in claim 1, further comprising a pressing member which presses said sheet-like substrate in a direction of thickness thereof. 
     
     
       11. A carriage-connecting device as claimed in claim 2, further comprising a pressing member which presses said sheet-like substrate in a direction of thickness thereof. 
     
     
       12. A carriage-connecting device as claimed in claim 4, wherein: said at least one narrow conductive strip is located at said one side of said first substrate;   a second narrow conductive strip is located at said one side of said second substrate; and   said at least one wide conductive strip is located at said another side of said first substrate.   
     
     
       13. A carriage-connecting device as claimed in claim 4, wherein: said at least one narrow conductive strip is located at said one side of said first substrate;   said at least one wide conductive strip is located at said another side of said second substrate; and   a second wide conductive strip is located at said another side of said first substrate.   
     
     
       14. A carriage-connecting device as claimed in claim 4, wherein: said at least one narrow conductive strip is located at said one side of said first substrate;   a second narrow conductive strip is located at said one side of said second substrate;   said at least one wide conductive strip is located at said another side of said first substrate; and   a second wide conductive strip is located at said another side of said second substrate.   
     
     
       15. A carriage-connecting device as claimed in claim 4, wherein: said at least one narrow conductive strip is located at said one side of said first substrate; and   said at least one wide conductive strip is located at said another side of said second substrate.